Answer:
An ice cube melting is a physical change because melting doesn't change the composition of the element. Paper burning is a chemical change because combustion occurs. Bubbles forming in a soda does involve chemical changes. Hard-boiling an egg is a chemical change because the egg's composition changed.
Hematite is a naturally occurring mineral and a common form of iron ore. The following statements describe physical and chemical changes occurring to hematite. Which statement describes a chemical change?
When the hematite particles rearrange to form a new substance", this statement describes chemical change.
What is chemical change ?A chemical change is a change of materials into another, new materials with different properties and one or more than one new substances are formed.
As a chemical changes is usually a change where a substance undergoes a chemical change and forms a new substance; which cannot be easily reversed into reactants by any simple physical methods.
In this example the hematite ore forms a new substance by an irreversible chemical change.
Hence, "The hematite particles rearrange to form a new substance", this statement describes chemical change.
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A 150 j of energy is added to a system that does 50 j of work is done. By how much wiull the internal energy of the system be raised?
Answer:
thnx for the points too muchee
Explanation:
Answer:
3 internal energyExplanation:
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One problem with using pesticides to control insects on crops is that the insects can develop resistance to the chemicals. How is this similar to the overuse of antibiotics?
Answer:
Explanation:
Overuse of antibiotics leads to bacteria's resistance against our drugs. This is increasing at an alarming rate and the reason is that overuse of antibiotics kills bacteria that lack the "resistance" gene or gene that can help them survive the antibiotics (similar is the case for insects that die to insecticides). But, some bacteria can have random mutations in their gene that can help them survive the antibiotic (similar is the case for some insects that can survive the insecticide), thus the surviving bacteria give rise to next generation of bacteria that are resistant to the given antibiotic (similar to how insects that survive the insecticide give birth to new insects that are resistant to insecticide too). Soon, every generation adds new antibiotic resistant bacteria (or new insecticide resistant insects in the case of insects) which is dangerous for all of life on this planet. Therefore, both are similar in the sense that new generations of these organisms will be resistant to our weapons against them.
The biosphere is made of different kinds of matter. Which substance is an
example of inorganic matter?
O A. Iron
B. Fat
C. Glucose
D. Protein
define hydroscopy in chemistry
Answer: A hygroscopic substance is one that readily attracts water from its surroundings, through either absorption or adsorption
Explanation:
Describe the energy in natural gas and the way in which it’s converted to electrical energy.
Calculate the average atomic mass for element X
Answer:
39.02amu
Explanation:
According to this question, there are four (4) isotopes for element X with the following relative abundance:
Isotope 1 = 9.67%, mass no: 38
Isotope 2 = 78.68%, mass no: 39
Isotope 3 = 11.34%, mass no: 40
Isotope 4 = 0.31%, mass no: 41
To find the average atomic mass of element X, we multiply each isotopes' relative abundance by its mass no and find the sum as follows:
We convert each percentage to decimal abundance:
Isotope 1 = 9.67% = 0.0967
Isotope 2 = 78.68% = 0.7868
Isotope 3 = 11.34% = 0.1134
Isotope 4 = 0.31% = 0.0031
(0.0967 × 38) + (0.7868 × 39) + (0.1134 × 40) + (0.0031 × 41)
3.6746 + 30.6852 + 4.536 + 0.1271
Average atomic mass = 39.02amu
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Answer: 1.80
Explanation:
How do you think the bonds between carbon atoms might be different in diamond and graphite?
Both have Giant Covalent Structures, resulting in very high melting temperatures. However each carbon atom in Diamond has 4 covalent bonds with other Carbons, making it extremely strong and hard. On the other hand, each carbon in graphite is bonded to three carbons, and therefore graphite is formed in layers.
Anthracite coal d) is the most abundant grade of coal e) is very soft and burns at high temperatures a) causes the most air pollution c) is very hard and burns cleanly b) has the highest sulfur content
Answer: The correct option is C ( is very hard and burns cleanly).
Explanation:
COAL is a form of rock that is made up of mostly carbon amongst other elements which includes sulphur, nitrogen, hydrogen and oxygen. There are different types of coal which include:
--> anthracite ( 90% carbon)
--> bituminous coal ( 70-90% carbon)
--> lignite ( 60- 70% carbon) and
--> peat (60 % carbon).
Anthracite is the type of coal that contains the highest carbon content ( 90% carbon). This makes it very hard and is often a times referred to as HARD COAL. Anthracite is a higher quality coal for domestic and open fire heating. This is because it contains less impurities than other type of coal and thereby making it to BURN CLEANLY avoiding atmospheric pollution.
Gallium has two natural occuring isotopes: Ga-69 with 68.9256 amu and a natural abundance of 60.11%, and Ga-71 with mass 70.9247 amu and a natural abundance of 39.8%. Calculate the atomic mass of gallium.
¿Qué características distinguen a los coloides de otras mezclas?
2. Find the slope of the line that passes between the points (12,5) and (2,3).
Write your formula for Slope
m=y2 −y1/x2-x1
Explanation:
3-5/2-12=1/5
(Please help)
What is the most common isotope for element X
Answer:
Isotope 2
Explanation:
Isotope 2 is the most abundant. Its percent abundance is 78.68% which is the largest percentage, and therefore the most common of the isotopes presented.
Good luck!
What are the effects of acid precipitation in city centers
Answer:
Answer to the following question is as follows.
Explanation:
Acid rain causes harm to houses and buildings by dissolving stone or corroding metal exposed to the elements. Acid rain can degrade calcium carbonate or calcium-based chemicals found in some of these products.
The acidic particles damage metal and accelerate the deterioration of paint and stone. They also make buildings and other structures, like as monuments, filthy.
Please can someone answer quickly this do tomorrow morning
Which of the five signs should not be used by themselves?
Precipitate
Temperature change
Color change
Odor
Bubbles
Temperature change
Pls corret my answer if its wrong ●~●#CarryOnLearningMike watch 100 m north then watch 30 m south after this he walks another 10 m north what is the magnitude of his total displacement during this walk in meters
Answer:
His total displacement is 80 m northwards
Explanation:
Given;
Mike's first displacement, x₁ = 100 m North
Mike's second displacement, x₂ = 30 m South
Mike's third displacement, x₃ = 10 m North
Let his Northwards direction be positive, and
his Southwards direction be negative
His total displacement = (100 m North) + ( - 30 m South) + (10 m north)
= (100 m + 10m - 30 m)
= 80 m Northwards
During a process called photoact, ________ give up an electron as a part of the light-dependent reactions.
Answer:
Chloroplasts?
Explanation:
explain the chemical reaction
A chemical reaction is when reactants are converted into another substance (also called products). Their reaction rearranges the constituent atoms of the reactants to give different substances as products.
I hope this helps! Please mark me as brainliest!
Have a wonderful day!
Please a little help in this I will really appreciate it
Answer:
b is your answer...........
The table shows four reactions.
Reactions
Reaction Equation
1 C3H8 + 5O₂ → 3CO₂ + 4H₂O
2 C₂H4 + H₂ → C₂H6
3 AgNO3 + NaCl - AgCl + NaNO3
4 2Fe + O₂ → 2Feo
Which of the above reactions is an example of combustion of an organic substance?
a) 1
b) 2
c) 3
d) 4
Answer:its B
Explanation:
i have done this before! and i got 100 so i hope you got all the other questions right!
The table shows four reactions. The reaction That is an example of combustion of an organic substance is C₂H₄ + H₂ → C₂H₆. The correct option is b) 2.
What are combustion reactions?Combustion reactions are those reactions in which the reactant reacts with oxygen and produces heat and light. An example is the burning of wood, it happens in the presence of oxygen.
Organic compounds are those compounds that are made by carbons. They are made by carbon-carbon or carbon-hydrogen bonds. They are naturally present in nature.
C₂H₄ + H₂ → C₂H₆
The equation above shows the reaction between methane and hydrogen, which is forming ethane in the presence of oxygen.
Thus, the correct option is b) 2. C₂H₄ + H₂ → C₂H₆.
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Where would (aq) (s) go in Cr(NO3)3+K3PO4
Answer:
Cr(NO3)3 (aq) +K3PO4 (s)
Explanation:
a que llamamos niveles y subniveles de energia?
Answer:
agua
Explanation:
por que estamos en la planeta
why atoms of magnet differ from normal atoms?
Copied answers ❌❌❌
Answer:
The magnetic field of an atom, say H (one electron revolving around a proton) is composed of two separate contributions: an orbital magnetic moment and a spin magnetic moment. We get magnetic moments because of electromagnetic induction associated with each type of electron motion. The electron revolving around the proton with a certain angular momentum is related to the associated orbital magnetic moment (and, yes, we model it as a wire loop with current expressed in terms of the orbital velocity). This can be calculated using elementary mechanics. The spin magnetic moment is a little trickier because it is caused by the intrinsic spin of the electron which is a quantum phenomenon; therefore, this spin magnetic moment can only be calculated using quantum mechanics. In the end, we get a certain net magnetic moment associated with this motion of the electron in an atom. It is important to notice that this atom acts as a magnetic dipole (remember, as of yet, magnetic monopoles don't exist!).
If we take a bulk magnet like you might have on your fridge, it would be composed of atoms. Each atom operates as a magnetic dipole, but due to internal atomic structures, the atoms actually align themselves into separate magnetic domains, each with a net magnetic moment (caused my individually adding up those atomic dipole moments). In a common magnet (ferromagnet), these domains all point the same direction and stay that way, creating a permanent bulk magnetic dipole.
So in a way, there is no difference between the magnetic field of an atom and that of a magnet because one is simply a sum of the other, making both magnetic dipoles. Of course, here we see that there's nothing that fundamental about the magnetic force. In reality, the magnetic force is a relativistic effect caused by the movement of a charged particle, making electricity (i.e. charge) the underlying property at work here. Electromagnetic induction is really a shortcut to understand the magnetic force without worrying about relativistic mechanics. If we were to discover magnetic monopoles (i.e. "magnetic" charge), this would re-write a lot that we know about electromagnetism because we couldn't label all magnetic forces as by-products of moving electric charge
if drop a watermelon from the top of one of the tower dorms at CSU, and it takes 3.34 seconds to hit the ground, calculate how tall the building is in meters and then convert into feet.
Answer:
179.5 feet
Explanation:
54.718 m converted to 179.5 feet.
The table shows the charge on three unknown subatomic particles.
X positive
Y no charge
Z negative
Which particle is most likely present in the space outside of the nucleus of the atom?
Answer:
Z negative
Explanation:
The negative charge shows that this is an electron. Electrons are present outside the nucleus of the atom and having negative charge. Usually represented by e-
Answer:
Only Z?
Explanation:
How can I balance chemical equations by providing the correct coefficients? For example: [?]Pb(NO3)2 + [?]NaCrO4 = [?]PbCrO4 + [?]NaNO3
Answer:
Pb(NO₃)₂ + Na₂CrO₄ —> PbCrO₄ + 2NaNO₃
The coefficients are: 1, 1, 1, 2
Explanation:
Pb(NO₃)₂ + Na₂CrO₄ —> PbCrO₄ + NaNO₃
The above equation can be balance as follow:
Pb(NO₃)₂ + Na₂CrO₄ —> PbCrO₄ + NaNO₃
There are 2 atoms of Na on the left side and 1 atom on the right side. It can be balance by writing 2 before NaNO₃ as shown below:
Pb(NO₃)₂ + Na₂CrO₄ —> PbCrO₄ + 2NaNO₃
Now the equation is balanced.
The coefficients are: 1, 1, 1, 2
if sneezing is the response to smelling food is it conditioned or unconditioned
Answer:
i think its unconditioned response.hope it helpsstay safe healthy and happy.Help me please I really need this tomorrow
19. place moth balls in the closet and observe after several days.
20. whenever wax or a candle burns it turns from solid to liquid but again at room temperature it turns to solid
21. evaporation, condensation, precipitation
22. it produces new substances
23. vinegar Bubbles when baking soda is added
24. steam